Chau made $105 for 7 hours of work. At the same rate, how much would he make for 13 hours of work?

Can someone me with this problem . show your work .

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.